Chapter 7: Excretion Lecture Notes

A set of vocabulary flashcards covering the human excretory system, the organs involved, the structure of the nephron, and the process of urine formation.

Excretion

The removal of metabolic waste and the process of ridding the body of any materials that are in excess supply.

Metabolism

All the chemical reactions that occur in a living cell.

Aerobic Respiration Equation

$$Glucose + Oxygen \xrightarrow{\text{Enzymes}} Carbon\,dioxide + Water + Energy$$

Urea

A metabolic waste product formed from the deamination of excess amino acids in the liver.

Bile

A waste product formed from the breakdown of old red blood cells in the liver.

Lungs

The excretory organs responsible for excreting carbon dioxide during exhalation.

Liver

The organ that excretes bile formed by the breakdown of old red blood cells.

Skin

An organ whose sweat glands produce sweat (mostly water, salt, and urea) which evaporates to cool the body.

Kidneys

The main organs of excretion that filter blood to remove urea, excess water, and salts to form urine.

Renal artery

The blood vessel that brings blood to the kidney to be filtered.

Renal vein

The blood vessel that carries filtered blood away from the kidneys toward the heart.

Ureters

Tubes that connect the kidneys to the urinary bladder to carry urine.

Urinary bladder

A saclike organ with muscular walls that stores urine before it is pushed out of the body.

Urethra

A tube through which urine is carried from the bladder to the outside of the body.

Nephrons

The microscopic filtering units of the kidney; each kidney contains at least one million of them.

Glomerulus

A knot of capillaries within the nephron where the filtering process begins.

Bowman's capsule

A cup-shaped structure surrounding the glomerulus that connects with a tubule.

Filtering

The process where small molecules (water, urea, salt, and glucose) are forced out of the glomerulus into the Bowman's capsule under high pressure.

Reabsorbing

The process occurring in the tubules where substances the body needs (glucose, some water, and salt) are absorbed back into the blood.

Collecting duct

The tube that removes urine from the nephron and passes it into a ureter.

Kidney failure

A disorder where one or both kidneys stop working due to infection or injury, treated by dialysis or kidney transplant.